To flip the conversation, I hate cooking for people 'who'll eat anything'..... It's pointless, dull and unrewarding.
I have two friends like this, and they really will eat anything. Doesn't matter whether it's cheap or expensive, well done or rare, not in a sauce/in a cheese sauce/in a tomato. It's food, in front of them and there, so they shovel it in chew and swallow.
Where's the incentive to try? They'll eat anything I put in front of them, so why should I spend time and money on them? The feedback on McD's is the same as on Slow-Roasted Venison in Blackcurrant Jus. It's all just food.
I prefer fussy eaters. I prefer people who have likes and dislikes. I enjoy creating a meal that people actually will enjoy, and because of that, I've seen, so often, people obviously relax, and smile and enjoy a meal away from home, in some cases for the first time ever.
And I've been on the other side. I have texture, not taste, and there is a serious difference, issues. I love read meat, but I almost never order meat when out, because I cannot cope with gristle or fat or bone.
And if I say this to someone, and they invite me for dinner, and then try to serve me cheap, undercooked steak, and I refuse, I'm seen as fussy.
But I see it as the host being rude, tbh, and worse, if they then start commenting and 'encouraging me' it's comes across quickly as bullying, which is just as unappealing as 'fussing'.
If you invite someone over for dinner, and you ask them what they will and won't eat, don't whinge if you serve outside that range and they complain. If their list of will/won't is too long, don't invite them back.
TBH, a lot of this issue would go away if people stopped branding people 'fussy'. If people felt they were able to be honest about their likes/dislikes, and had it accepted, without judging, then they would be, and then hosts would know what they could/could not cook and everyone would be happy.
Children are different, as they are still learning about food but an adult surely, must have the right to say 'I don't like that', without being judged, lectured, pressured or sneered at. If that list is chicken-nuggets-and-chips... so what? It isn't affecting you unless you let it!
I do agree, though, that when it comes to work do's or social occasions, there does have to be a limit - but, again, both ways. Picking somewhere reasonably middle of the road with a choice of meals is really the only fair thing to do. Non-fussy (or choosy or selective or discerning....) people who will 'eat anything' sometimes don't realize what a stretch certain restaurants can be for others and are downright rude about it in return.